Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Int J Biometeorol. 2019 May;63(5):579-590. doi: 10.1007/s00484-017-1377-2. Epub 2017 May 25.
Existing evidence demonstrates that the first flowering date (FFD) of most plant species became earlier in response to temperature increase over the past several decades. However, the studies on changes in flowering duration (FD) were limited. By using the non-parametric Theil-Sen estimator, this study investigated the temporal trends in 127 time series of FFD, end of flowering date (EFD), and FD of 97 woody plants from 1963 to 2014 at three sites (Harbin, Beijing, and Xi'an) in North China. The relationship between flowering phenophases and temperature was analyzed using two phenological models. The results showed that most of FFD and EFD time series exhibited an apparent advancing trend. Among them, trends of 52.0% (40.9%) of FFD (EFD) time series were significant (P < 0.05). FFD and EFD time series (95.3 and 89.8%, respectively) responded negatively and significantly to preseason temperature (P < 0.05). The direction of FD changes varied among sites and species. On average, a shortening trend of FD was observed at Harbin (-0.51 days decade), with 7.5% of species significantly. However, FD on average extended by 0.42 and 0.93 days decade at Beijing (24.5% significantly) and Xi'an (28.9% significantly), respectively. The regression models could simulate the interannual changes in FFD and EFD with the mean goodness of fit (R) ranging from 0.37 to 0.67, but fail to simulate the changes in FD accurately (R ranging from 0.09 to 0.18). The growing degree day model could improve the R for simulating FFD and EFD except for FD. Therefore, more phenological models need to be tested, and more drivers of FD need to be further investigated.
现有证据表明，在过去几十年里，大多数植物物种的首次开花日期（FFD）因温度升高而提前。然而，关于花期持续时间（FD）变化的研究有限。本研究利用非参数 Theil-Sen 估计器，调查了华北三个地点（哈尔滨、北京和西安）1963 年至 2014 年 97 种木本植物的 127 个 FFD、开花末期（EFD）和 FD 时间序列的时间趋势。使用两个物候模型分析了开花物候期与温度之间的关系。结果表明，大多数 FFD 和 EFD 时间序列表现出明显的提前趋势。其中，52.0%（40.9%）的 FFD（EFD）时间序列趋势显著（P<0.05）。FFD 和 EFD 时间序列（分别为 95.3%和 89.8%）对 preseason温度呈显著负响应（P<0.05）。FD 变化的方向在不同地点和物种之间有所不同。平均而言，哈尔滨的 FD 呈缩短趋势（-0.51 天/十年），其中 7.5%的物种显著缩短。然而，北京（24.5%显著）和西安（28.9%显著）的 FD 平均分别延长了 0.42 和 0.93 天/十年。回归模型可以模拟 FFD 和 EFD 的年际变化，平均拟合度（R）范围为 0.37 至 0.67，但无法准确模拟 FD 的变化（R 范围为 0.09 至 0.18）。生长度日模型可以提高 FFD 和 EFD 的 R，除 FD 外。因此，需要进一步检验更多的物候模型，并进一步研究 FD 的更多驱动因素。
